Masks are better if we are doing any activity that raises our heart rate and breathing ? bicycling, running, vigorous walking, etc. Vogmask is a highest filtering anti-air pollution masks for babies, children and adults. People who have found Vogmask most helpful are those with allergies, wheezing, fragile immune systems, travelers, commuters, bicyclists, hikers, walkers, hobbyists, or anyone who is outdoors when air quality is hazardous. The N99 and the Active Carbon filter protect from the following: PM 2.5 particles – as tiny .3 micron particles, Dust, Germs, Pollen, Mold spores, Allergens, Bacteria, Other airborne contaminants.